Table of Contents

Introduction

A brief walkthrough on setting up your first docker swarm1

Getting Started

It may go without saying that you need to have docker already installed[^fn2] before proceeding, but assuming docker has been installed on all hosts, then creating a swarm is trivial. First choose the initial manager node (this is simply the node that you want to manage the other nodes in the cluster). If you are working with a single node cluster (i.e. one host machine) then that will be your manager.

Login to the initial manager node and execute the following:

$ docker swarm init

Swarm initialized: current node (y4vkoat0deioflw53cb2ie0ij) is now a manager.

To add a worker to this swarm, run the following command:

    docker swarm join --token SWMTKN-1-1ce9a31d1c3b4b1ce9a31d1c3b4bdf52a1aea30359c712-5cggaqt83z5b26w17lceb7if9 192.168.100.20:2377

To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.

Basically the output of the command is telling you that it has create the swarm and set the current node as manager. It also tells you to run the following command on the worker nodes:

$ docker swarm join --tokenSWMTKN-1-1ce9a31d1c3b4b1ce9a31d1c3b4bdf52a1aea30359c712-5cggaqt83z5b26w17lceb7if9 192.168.100.20:2377

Every node (i.e. host machine) on your network that you run the above command on will join the swarm you just created and print out the following:

This node joined a swarm as a worker.

This lets you know that you have successfully added a new worker node to the cluster. (NOTE: if you have a single node cluster this is not necessary as the managing node is the only node in the cluster).

The last bit of information you are given in the above docker swarm init command tells you how to add more managers to the cluster:

To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions.

With this your initial cluster is complete.

References

  1. Docker Swarm ↩